A2
one single time
Dictionary examples:
I tried speaking French once. Even I didn't understand myself. (0.0)
I tried cooking once. The fire department came for dinner. (0.0)
My brother tried magic once. He made his homework disappear forever. (0.0)
I go swimming once a week. (11.7)
Once a year we all meet up. (13.2)
We have lunch together once a month. (14.2)
I went sailing once, but I didn't like it. (22.3)